How to Play the Altered Scale on Guitar

Jazz is about building and releasing tension.

One of your best tools for building tension is a dominant chord. You can increase this tension by ‘altering’ the extensions (colour notes) of a plain dominant chord. If you alter a dominant chord to it’s most extreme, the notes you play are the altered scale – the second mode of the melodic minor scale. This scale is the 7th mode of the melodic minor scale and is also known as the diminished whole-tone scale.

Use this lesson to:

Understand the theory behind this scale.

Learn the easiest approach to improvising with it.

Accustom your ears to its sound.

Have fun while learning.

This lesson is detailed and extensive so take your time!

A Small Secret (don’t tell anybody)

The altered scale is one of THE most powerful scales in the UNIVERSE. Jimi Hendrix knew about this scale (kind of), so it must be awesome. First things first, lets check out our Alt chord. Chords and scales go hand in hand. Your first step in learning any mode is to play the corresponding chord and tune your ears to its sound. If you need some Altered Dominant voicings, check out a few here.

Before we get too far, what does ‘Altered’ actually mean?

What notes are in an altered chord? Feeling confused? Let’s take an example to clear this up; Dm7 G7Alt Cmaj7. This is your common major II V I chord progression.

A fully altered G7 would be G7b9#9#11#5 but that looks really messy like a dog’s breakfast. Jazz musicians simplify this by writing G7Alt. Easy right? It is actually unpractical to play all of those extensions so you have the power to choose which extension you include in G7Alt Chord.

G7Alt could be any of the following:

G7#5

G7b9

G7b5

G7#9#5 (most common)

any combination of the above.

The following chords DON’T function as G7Alt

G13b9

G7#11, G9#11, G13#11,

any chord with a major 9th or 13th.

These chords use a different scales.

The Altered Scale

Can you see how it shares the same notes as C Melodic Minor? If this is doesn’t make sense, I recommend you have a basic understanding of the melodic minor scale before continuing.

Here is how to play this scale on the guitar, in two positions. Numbers indicate fingers. The white circle is the root note of the scale.

How to HEAR the Altered Scale (a little trick)

To start off with, it is handy to relate this mode back to its parent melodic minor scale. But to really HEAR the unique sound of a mode you need appreciate this scale as its own entity.

Try this:

Forget about the parent melodic minor scale.

Record an Alt chord and play through the scale slowly.

Accustom your ears its sound.

Try this with all your modes, think of each mode as its own unique scale.

To sum up, modes are easy to learn because they share the same notes as each other. But to get your ears around them, think of each mode as a unique scale and key centre. I remember modes being confusing to me when I started out, let me know in the comment section below if this trick works for you!

The Altered Scale; Under the Magnifying Glass.

Let’s take out our jazz-magnifying glass and examine this scale.

A dominant chord, by definition, needs to have a root, a major 3rd, and b7. The tritone interval between the 3rd and b7 is the core sound in a dominant chord. It is bursting with tension (and power). The Altered scale adds both a b9 and #9. Jimi Hendrix knew about the aggression of the #9 when he rocked out on a dom7#9 on ‘Purple Haze.’ The Altered Scale also has a #11 (b5) and b13 (#5), which adds EVEN MORE tension.

Altered Summary

Scale

Altered Scale

Chord

Dom7 Alt, Dom7b9, Dom7#9, Dom7#11, Dom7#5, or any combination of the above.

Notes

R, b9, #9, 3, #11, b13, b7

C Example

C, Db, D#, E, F#, Ab, Bb

Chord/ Guide Tones

b3, b7

Color Tones

b9, #9, #11, b13

Avoid Notes

none!

Sam's Tip

This is your weapon of mass-jazz-awesomeness (in a good way). It has strong harmonic flavors and melodic power. Use it well and use it wisely.

When To Use The Altered Scale

With great power comes great responsibility. The altered scale contains powerful tension, so knowing when to use it is vital. First, a little word about dominant 7 chords.

When you come across a dominant 7th chord in a tune, you as an improviser have many options of what scale to play. Which scale you choose depends on a few factors: the style of jazz (old, modern, bebop, smooth jazz, etc), your personal style (what you want to say with your music), and most importantly – what the arranger or composer has envisioned when he created the piece of music.

With this in mind, the general rule for using the altered scale is: use it on dominant 7 chords functioning as V7 chords.

For example:

F7 Bb | Playing F Altered scale on F7 will pull nicely towards Bbm.

G7 Cmaj7 | Playing G Altered Scale on G7 will create a strong pull towards Cmaj. I recommend you check out the {half-whole diminished scale} for a less abrasive option for dominant 7 chords resolving to major chords.

How to Learn the Altered Scale

Follow these 3 steps to get your EARS around this scale:

Play it a few times, up and down.

Record a dom7#9#5 chord. Play the scale and listen to how each note sounds.

To get your FINGERS around the Melodic Minor Scale, I recommend you check out, How to Practice Jazz Guitar Scales. Apply the patterns I use in that lesson to get your muscle memory happening. Spend some time on this scale. It has a lot of spicy notes and is a fantastic tool for building tension. Play around with it, and most importantly – have fun!

Great Job, Keep Learning

Once you feel comfortable with this scale, here is some further reading I recommend you check out:

The Lydian Dominant Mode – 4th mode of the Melodic Minor Scale. You can tritone substitute any altered chord with a dominant 13#11 chord a tritone away. The Lydian Dominant Mode is what you use on that new chord.